Aim:

We aimed to investigate the effects of MgSO4 used during induction and maintenance of general anesthesia on anesthetic drug requirement, consumption of muscle relaxants, preoperative hemodynamics, postoperative reco- very, and postoperative analgesia in patients scheduled for thyroid surgery.

Material and Methods:

Fifty patients (ASA I-II) were randomly allocated into two groups; Group M received 30 mg kg-1 MgSO4 15 minutes before induction followed by 15 mg kg-1 h-1 MgSO4 infusion, and Group K 0.9 % NaCI. Anesthesia was induced with intravenous administration of 20 mg propofol, 1 µg fentanyl and 0.6 mg kg-1 rocuroni- um every 5 seconds keeping BIS at 60. 1 mg kg-1 i.v. for the maintenance of anesthesia sevoflurane was used so as to keep BIS between 50, and 60. Tramadol (1 mg kg-1 iv) was used for postoperative analgesia. Postoperative analgesia level was recorded at 10., 20., 30. min and 1., 2., 3., 6. h using Visual Analogue Scale (VAS), and 75 mg diclofenac sodium iv. was administered to patients with a score of 5 or higher. Kolmogorov-Smirnov, Student’s t, Man-Whitney U and Chi-square test were used for statistical analysis.

Results:

Postintubation and intraoperative 15. minute MAP and HR values were significantly higher in Group K patients. Propofol requirement at induction, and FI % for sevoflurane, at maintenance and total rocuronium consump- tion were significantly lower in Group M. T1 10 % and T1 25 % response times were delayed in Group M. Extubation time, response to verbal stimuli, verbal response time, and time to reach a score of 10 modified Aldrete score of 10 were found to be prolonged in Group M. In Group M, 10., 20., 30. min VAS scores were lower, and time to the first requirement for an analgesic was also delayed.

Conclusion:

Peroperative MgSO4 use decreases intubation-related stress, and anesthetic drug usage during induc- tion and maintenance phases of general anesthesia, potentializes the effect of rocuronium, decreases postoperative side effects and has a positive effect on postoperative pain control.

Keywords: Magnesium Sulfate, thyroid, rocuronium